Chair iron



1939. D. R. COLLIEIR ET AL 2,184,989

CHAIR IRON Filed May 8, 1937 I Patented Dec. 26, 1939 UNITED i, STATES CHAIR IRON David R. Collier and Henry W. Sheldrick, Gardner, Mass; assignors to Collier-Keyworth Company, Gardner, Mass, a corporation of Massachusetts Application May 8, 1937, Serial No. 141,474

f 4 Claims.

This invention relates to chair irons for ofiice chairs or the like, having backs which yield rear wardly against spring pressure from an adjusted initial position and which are also vertically adjustable.

It is an object of the invention to provide a clamping device to hold the back in vertically adjusted position having a control member oiTset to a side of the chair iron for ready accessibility by the occupant of the chair.

It is another object of the invention to provide a back which can quickly and easily be removed from and returned to the chair structure.

It is a further object of the invention to provide a structure such that the rear of the chair is free from undesirable projections.

For a more complete understanding of the invention, reference may be had to the disclosure of an embodiment thereof in the following description, and in the accompanying drawing of which:

Figure 1 is a rear elevation of a chair embodying the invention.

Figure 2 is a fragmentary section on the line 2 2 of Figure 1. Figure 2a is a sectional view on line 2a-2a of Figure 2. v Figure 3 is a fragmentary section on the line -33 of Figure 1.

Figure 4 is a section on the line 4-4 of Figure 3.

Figure 5 is a perspective of the structure.

As illustrated'on the drawing, the invention may be embodied in a chair iron for-office chairs such as the one illustrated in Figure 1, this chair having the usual base or pedestal I0 into which projects the spindle l2 of the chair iron, generally indicated at I4. A seat I6 is mounted on the iron and the chair also includes a back I8 which is rockable rearwardly against the pressure of a spring 26 illustrated in Figure 2. The structure of the chair-iron for the most part is shown 45 as similar to that described and illustrated in the application of Henry W. Sheldrick, Serial No. 84,277, filed June 9, 1936. As therein shown, the chair iron may comprise a seat support having a pair of longitudinally extending members 24 to which ispivotally attached, as at 26, a member consisting of a pair of side plates 30 connected by a bridging piece 32 so that this member rocks as a unit about a horizontal axis passing through the pivots 26. Such rocking movement is against the spring 20 which is supported by a bolt 34 projecting. through and having a head supported on a transverse frame element 36 which extends between the longitudinal members 24. The lower end portion of the bolt 3 is threaded to receive a nut'or hand wheel 38 against which the lower view of certain parts adjusted relatively tothe rockable member but M can rock as a unit with that member about the pivots 26. The angular relation between the bracket ll] and the rockable member may be controlled by any suitable device, such as a link 46 which is connected at one end to the upper portion of the bracket 40, and at the other end to an approximately horizontal bell crank 5U which is rockable about a pivot 52 so as to pull or push the link it. The bell crank 50 is actuated by the rotation of a shaft 54 which is in threaded engagement with an element 56 pivotally attached as at 58 to the bell crank 50, or as more "fully illustrated and described in the said Sheldrick application Serial No. 84,277. The shaft it extends transversely with respect to the chair, asuitable hand wheel til being preferably mounted at its outer end so as to be conveniently reached by the occupant of the chair. Rotation of the hand wheel W thus controls the angular relation between the back bracket All and the rockable member so that the'normal position of the back 18 is thus adjusted, from which normal position the back will yield rearwardly under pressure together with the bracket 40 and the 1 rockable member rocking as a unit about the pivots 26.

According to the present invention, improved structure is provided for adjustably securing the back It to thebracket 40. To this end, the bracket is provided. with a vertical slot ill which extends upward from the lower end of the bracket nearly to the top thereof. In order to compensate for the weakening of the bracket by this'slot, I a channel member '12 is provided to span the slot, this channel member prererably extending from the top to the bottom of the bracket 40, as indicated in Figure 2. The back It is directly mounted upon a back plate 74 which engages the back of the bracket ii at the corners, as indicated in Figure 3. This side edges as at 18 to form stiffening flanges. In

' order to clamp the plate 14 tightlyv against the bracket lll, a plate'80 is provided which is preferably bulged rearwardly both longitudinally and transversely, asindicated in Figures 2. and 3. The plate 80 is secured to the outer end of an element 82. This element extends through the slot I and has a head 84 engaging the front face of the bracket 40 within the channel of the member'lf. The element 82 also extends through an aperture 85 in the plate M and also through an aperture 85 in the plate 80 and is headed-over against the outer face of the plate BELas-indicated inFigure 3. In order to clamp the back plate 14 in adjusted position, a wedging, element-is provided consisting of a shaft I00 having a tapered end I02 entering between the plates i4 and 89. *The shaft .;I00;1has; a;.threaded portion I04 which is in gthreadedscngagement.withan ear I06 at an end of the plate 'i l. The, tapered end I02 of the shaft emaygbeisuitably, guided by therounded heads of ,a pair of,.rivets II 0 which are secured through ,thep1ate'80. The heads of these rivets'may also provide a purchase for thexwedging effect of the itapered end I02. On the outer end of the shaft ,I,iI0 ,may-; be mounted ahand wheel I I2 by which .theshaft may conveniently be operated bythe 25, occupant .of thechainthis operating wheel II2 being located,,as indicated in Figure 1, at the side ;,of the-seatrso as to be within easy reach. -Eotat ion of the shaft I00in one direction causes thetapered end I02 to advance toward the left and to wedge the adjacent end of the plate 80 away'fromthe plate I4 and its opposed end portion against the back face of the plate, both these ,actionsfor cing,theplate l4 forward against the bracket A0 whichit-engages along the roots of the fl n es A l mpin i n dj t d po it on- When the shaft j 001s backed away toward the right, theplate 14 with its back I8, isreleased for vertical adjustment, the element 82 then riding in the slot 10. The hand wheel [I2 is so positionedthat itmaybegraspedby, one hand of the chairoccupantyvhile hegrasps the back of the chaironthcopposite side with the other hand. The-back may then be loosened, .adjustedto suit the occupant While he is in a ,normal sitting. posi- 5 ,tion, ,andthen tightened. ,In orderto keep the plate 80 roughly, parallel toflthe plate 1.4 when the .former is loosened,,ears I0;5. are prQVided on theplate ,80 to extend forward, overlapping the .llpper flan es .-'I 8, of the ,plate .14. The aperture ,06 is shown ,as,above the horizontal center of the plate 80 in order to increase the ,efiective lever arms to the points oftengage ment of the plate 80 a ainstthe plate I4 to better resist backward pressureexerted on the chair back by the occupant. Since the slot 1,0 is open at its lower end, theback assembly (consistingtof the back I8, the plate 114, the lever 80 and the bolt .82) may be moved from thebracket .40 as a unit. In Order, toupr event this assembly from falling clear of thejbracket Q0 v v. l; 1,en i t1is desired only to adjust the back vertically, ,a catch is provided. This catch, as indicated in Figure2, may consist of va tongue struck up .froma strip of spring metal I22 which is secured at its upper endto the channel 5 member 12 as by a rivet I24. The tongue I20 projects through anaperture I26 in the lower portion of the channel member, the strip I22 or ,dinarily lying against the forward face of, the

channel member. The tongue I20 is thus in the 70 path of movement .of the bolt head 84 and normally acts to positively stop the downward movement of the bolt head so as to prevent the back assembly from becoming entirely disengaged from the bracket 40 in the course of vertical adjustment of the back. When, however, it is desired to remove-the back assemblyifromathebracket,

the lowerend I30 of the strip- I22 may be pressed toward the right, as indicated in Figure 2, so as --to retract the tongue I20 from the path of the head 04. This permits the ready removal of the back assembly from the bracket.

.From the foregoing des'bription'of an embodi- 1 mentof thisinvention, it should be evident to those skilledinthe-ert that various changes and modifications--may be made therein without departing from the spirit or scope of this invention as defined by the following claims.

We claim:

,1. A chairiron comprisinga .seatsupport, an 'upright back bracket carried by said seat :supportand havinga vertical slot. extending up from the .lower .edge thereoi,-.a channelmembensecured to the forward face of said bracketbridging said. slot, .avertically adjustable back plate engaging the back of-.said bracket, means for clamping said plate in adjusted position against .saidbracket, said clamping means including an element extendingflthrough saidslotand having a head disposed insaid channel, and. means 00- operating with said element to effect the clamping action, and spring-catch meansnear the lowerend of said slot normally disposed inthe path of said headlto-limit the downward move-I ment thereof.

2. A chair ironcomprising a seat support, a back bracket.'carried-.'by. said support, a backplate vertically adjustable on said bracket, and means for clamping saidplate in adjustedposition, said means comprising a .member positioned adjacent to said plate, an element attached to said memher and extending through said.plate-.andbracket,

said element having a head engagingthe .forward face of saidgbracket, and wedging means between said member and plate for pressing-said :plate against said bracket.

3. In a chair iron, an upright back bracket having a Vertical slot therein, a back plate :en-

aging the back of said bracket, and means for Clamping; said plate against said bracket in ad- 'justed position, said clamping means comprising a member behindsaidplate, an element extending rearwardly through said slot and plate and secured to saidmember between-the ends thereof,

saidelemen-t having ahead engaging the forward face of .said bracket and serving as a fulcrum for said member, and a rotatable shaft having a tapered :endengaging between said plate and vmember, said shaft having a threaded portion cooperating with -a portion of said plate to ad vance the tapered end axially when rotatedso as to rock said memberon its fulcrum and-clam said plate against said bracket.

4. In a chair iron, an upright back bracket,

a pair of transversely extending members behind said bracket,.one of said members having a-cen-' tral portion engaging the back of then-bracket axially by rotation to spread said members and thereby to clamp them against said bracket.

DAVID R. COLLIER.

i and bulging away therefrom, the other said mem- HENRY W. SHELDRICK. 

